voltage spikes between analog output triggers?

Hi, In our application, I am using a DAQ for acquiring data, performing some signal processing and send the data out through analog output. At this time, we are not concerned with latency. The logic flow of our code is as follows:

• acquire the data continuously (inf samples)
• use samplesacquiredfcn to run a function every 1 second
• in the function, get the data, do processing, use putdata() and start the ao, and stop ao after data is sent (stop ao is used in the next iteration, i.e when index>1).The trigger used is immediate.

This works fine except the fact that we see a spike after every second in the oscilloscope which is connected to analog output.

How to avoid this problem?

Thanks, Adi